Fluid pressure operated rotary torque applying device



Oct. 23, 1962 N. F. ATHERTON 3,059,683

FLUID PRESSURE OPERATED ROTARY TORQUE APPLYING DEVICE Filed April 1, 1960 3 Sheets-Sheet 1 I INVENTOR. E 4. 3/ 30 NEIL E flrHg'ev-anl BY M m77% ATTOC/VEY" Oct. 23, 1962 N. F. ATHERTON FLUID PRESSURE OPERATED ROTARY TORQUE APPLYING DEVICE 3 Sheets-Sheet 2 Filed April 1, 1960 IN VEN TOR.

NEIL FI Brazier-0N aka 234% m ATT'OENEY! Ocf. 23, 1962 N. F. ATHERTON FLUID PRESSURE OPERATED ROTARY TORQUE APPLYING DEVICE 3 SheetsSheet 3 Filed April 1, 1960 INVENTOR.

NE IL. F. HTHEemA/ BY United States Patent Office 3,59,583 Patented Oct. 23, 1962 4 Claims. (@l. 153-40) 1 This invention relates to fluid pressure applying devices and more particularly to devices of this type for applying pressure along a curved path.

According to the present invention an improved fluid pressure applying device has been provided which is capable of applying force along a curved path.

More specifically, the invention provides a device of the above type having means forming an arcuate displacement chamber, other means forming a complementary arcuate member extending into said chamber and movable in an arcuate path relative thereto, and means for supplying fluid pressure to said chamber.

These and other objects and advantages of the present invention will appear as this disclosure progresses, reference being had to the accompanying drawings in which:

FIGURE 1 is a generally front perspective view of a pipe bender embodying the present invention;

FIGURES 2 and 3 are side views, on an enlarged scale of the bender shown in FIGURE 1 and showing it at the beginning and the end, respectively, of a bending operation;

FIGURE 4 is a side elevational view, on a further enlarged scale, certain parts being shown in section and broken away;

FIGURE 5 is a bottom View of the bender;

FIGURE 6 is a view taken generally along lines 6-6 of FIGURE 4;

FIGURE 7 is a sectional view along line 77 in FIGURE 4;

FIGURE 8 shows a modified form of the invention, the view being a side elevation with certain parts in section and broken away; and

FIGURE 9 is a view taken generally along line 99 in FIGURE 8, with parts being shown in section or broken away for clarity in the drawings.

The invention will be shown and described as applied to certain specific uses such as a pipe bender or a rotary torque device for hub rotation work, but it should be understood that the invention is applicable to other fields and should not be limited to the forms shown here for illustrating the invention.

In addition, the invention is applicable to use with different types of pressure fluid, such as for example, oil or air.

Referring in greater detail to the drawings, and particularly FIGURES 1-7, a fixed frame F is provided which includes an upright member or plate 10 and a block 11 welded at the lower side of the plate and transversely in respect thereto. A reinforcing gusset plate 10a is welded between plate 10 and block 11. A fluid passage 12 extends through block 11 for purposes that will presently appear. A rotatable sheave or pulley 14- is mounted at the upper end of the plate 10. More specifically, the axis 15 on which the pulley is mounted is supported by and between the upper end of plate 11) and the upper end of a strap 16. The strap 16 is mounted at its lower end on a shaft 18 fixed to plate 10. Thus the fixed frame F comprises the plates 10 and 10a, block 11, pulley 14 and strap 16. While this frame has been described as being fixed, it should be understood that the bender shown in these figures is rather small and easily portable. By fixed is meant that it is stationary relative to the swingable force applying member S to be described.

A hydraulic pump P is secured by bracket 19 and screws 20 to one side of the frame F and the cylindrical reservoir 21 forms a handle for the bender which is grasped by the operator when in use. The pump includes a pumping lever 22 by means of which pressure fiuid can be supplied to the passage 12 which with the pump is in fluid communication. A manually operable release valve 13 opens the discharge side of the pump back to the tank when pressure is no longer desired in the system being served. The pump P is of conventional and well known design and further description of it is not believed to be necessary. It should be suflicient to say that it is of the general type shown in US. Patent 2,277,256 issued on March 24, 1942.

An arcuate shaped piston 25 is welded at its lower end to block 11. A passageway 26 extends axially through this piston and is in communication with passage 12 in block 11. This piston 25 forms an arcuate beam or fixed arcuate conduit which is formed with the shaft 18 as a center and may extend, for example, through an arc of about degrees.

The piston 25 and the frame 10 constitute a piston assembly on which is pivotally mounted a swingable housing to now be described.

A swingable housing in the form of a force applying member S is oscillatably mounted on shaft 18, is seg mental in form and has a U-shaped pipe trough or track 27 along its periphery to constitute a bending shoe. Swingable housing 8 has a pipe clamping means 29 adjacent one end of the track 27. This means includes a block 30 having an aperture 31 in which the end of the pipe to be bent is inserted. The block 30 is split as at 32 to form bifurcated ends 34 and 35. A screw 36 extends through end 34 and is threadably engaged in end 35, the screw having a thumb lever 37 fixed at its outer end by means of which the screw can be tightened to cause clamping action of the bifurcated ends on the pipe.

The swingable member S has an arcuately shaped displacement chamber 40 formed therein which is complementary in form to the piston 25 over which it oscillates. Sealing means or shaft seals 42, such as O-rings, leather washers or a combination of them, are carried adjacent the outer end of chamber 40 to form a sealing fit with the piston and a pressurizable and expansible chamber within the swingable member S.

The operation of the pipe bending device is as follows. The straight pipe 45 is inserted in the clamping means 29 when the swingable member S is in the starting position shown in FIGURE 2.

At this time the valve 13 is shut and the lever '22 is pumped to force pressure fluid through passage 12, passageway 26 and into the chamber 40. This causes the member S to swing about its pivot shaft 18, thereby pulling the pipe 46 under the guiding means in the for-m of a pulley 14 and bending it to conform to the arcuate track 27. After the member S has traveled its full distance, as shown in FIGURES 3 and 4, the valve 13 would be opened, thereby releasing the fluid pressure in chamber 40 back to the reservoir 21.

The action of the bender is such that a constant torque is applied along an arcuate path.

Referring now to FIGURES 8 and 9, the invention has been illustrated as applied to a rotary torque device for rotating a member that is fixed to a shaft. In this embodiment the rotating or swinging member 50 is secured by a key 51 to a shaft 52. Member 50 has an arcuate chamber 53 having a fluid pressure opening 54 in its wall through which pressure fluid may be admitted or exhausted via a flexible conduit 55, for example, from pump 56. Seals 57 are provided adjacent the outer end of the chamber for slidable and sealing engagement with the relatively stationary or fixed arcuate piston 60 which constitutes a curved beam or ram.

The seals may be of a molded neoprene, together with an O-ring, all shaped to fit the ram 60.

It will be noted that in this modification both the chamber 53 and piston 60 are generally rectangular in cross section. The piston is mounted at one end by cap screws 62, to a fixed or stationary frame 65. The piston and frame 65 constitute a piston assembly which would in this modification be secured through its flange 66 by bolts 67 to any suitable fixed part (not shown) of the machine with which it is used.

In this modification, the swingable housing 50 is capable of rotating through an arc of about 150 degrees, and the amount of angular travel, of course, depends on the volume of oil pumped into the chamber.

It is not necessary that the cross sectional shape of the chamber and its piston are similar. However, in either embodiment of the invention, the cross sectional size and shape of the piston is uniform throughout its length. The effective cross sectional area against which the pressure fluid can act is this cross sectional area.

Certain definite advantages are obtained, however, with a piston of rectangular cross section, and particularly one having its radial dimension greater than its width as shown in FIGURE 9. This is because the piston tends to straighten out, when in use, that is, the torque forces acting on the piston end tend to urge it from its arcuate position to a straight one. By utilizing a rectangular section rather than a round one, more effective use is made of the pistons cross sectional area because more of this area is located both radially outwardly and inwardlypf the center axis of the piston. Thus in a rectangular c'ros,s s ction piston, the compressive and tensile loads on the piston are better distributed, and the piston is better able to withstand the stresses which tend to straighten it when in use.

The present invention provides a compact, lightweight and economically produced, rotary torque actuator, capable of using high pressure hydraulic fluid for the power medium, and which actuator provides a constant torque throughout its angular stroke.

Various modes of carrying out the invention are contemplated as being within the scope of the following claims particularly pointing out and distinctly claiming the subject matter which is regarded as the invention.

I claim:

1.A fluid pressure operated pipe bender comprising a fixed frame, an arcuate piston rigidly secured at one end to said frame, a swingable member pivoted to said frame about an axis, said member having an arcuate chamber complementary to said piston for slidably receiving the latter therein, said member also having means for holding a pipe to be bent and including an arcuate guide track, sealing means between said piston and chamber so the latter can be pressurized, said arcuate chamber and arcuate piston formed with said axis as a center, and means for supplying fluid pressure to said chamber to cause said member to swing about said axis.

2. A fluid pressure operated pipe bender comprising a fixed frame, an arcuate piston rigidly secured at one end to said frame, a bending shoe pivoted to said frame about an axis, said shoe having an arcuate chamber complementary to said piston for slidably receiving the latter therein, sealing means between said piston and chamber so the latter can be pressurized, said arcuate chamber and arcuate piston formed with said axis as a center, and means for supplying fluid pressure to said chamber to cause said shoe to swing about said axis.

3. A fluid pressure operated pipe bender comprising a fixed frame, pipe guiding means on said frame, an arcuate piston rigidly secured at one end to said frame, a swingable bending shoe pivoted to said frame about an axis, pipe clamping means carried by said shoe, said shoe having an arcuate chamber complementary to said piston for slidably receiving the latter therein, sealing means between said piston and chamber so the latter can be pressurized, said arcuate chamber and arcuate piston formed with said axis as a center, and means for supplying fluid pressure to said chamber to cause said Shoe to swing about said axis.

4. A rotary torque applying device comprising, a supporting frame, a force applying member pivotally secured to said frame for rotation relative thereto, said force applying member having an arcuate displacement chamber therein, an arcuate piston fixedly secured at one end to said frame with its free end extending into said chamber, said piston being complementary in shape with said arcuate chamber and the axis of the arc of both said chamber and said piston being concentric with the pivotal axis of said member, sealing means between said chamber and said piston permitting relative sliding movement therebetween, means for supplying fluid under pressure to said chamber to cause said force applying member to rotate relative to said frame and means for attaching a workpiece to the forward end of said member to transmit rotary force thereto, said member having an arcuate bearing surface for said workpiece extending rearwardly from said attachment means.

References Cited in the file of this patent UNITED STATES PATENTS 326,117 Horton Sept. 15, 1885 374,968 Kadel Dec. 20, 1887 1,076,120 Hobbs Oct. 21, 1913 1,111,605 Moss et al. Sept. 22, 1914 1,193,318 Velturn Aug. 1, 1916 2,620,848 De Paoli Dec. 9, 1952 2,902,009 Ludwig et a1 Sept. 1, 1959 FOREIGN PATENTS 634,607 Great Britain Mar. 22, 1950 659,453 Great Britain Oct. 24, 1951 503,122 Canada May 25, 1954 

